Argonne National Laboratory,
Keywords: x-ray, characterization
Summary:To be able to control the functions of engineered multicomponent nanomaterials, it is essential to understand heterogeneous nucleation at nanoscale in real time and real environment. To this end, X-ray scattering has been employed to reveal non-traditional growth mechanisms of hetero-nanomaterials for catalysis. In this talk, we will briefly review nanoparticle growth mechanism studies using in situ small angle x-ray scattering (SAXS) and wide angle x-ray scattering (WAXS) and further discuss our recent results on growth of the hetero-nanostructure using simultaneous SAXS and WAXS. In the study, by using in situ synchrotron X-ray scattering, we showed that in the heterogeneous nucleation and growth of Au on Pt or Pt-alloy seeds the hetero-epitaxial growth of the Au shell exerts high stress (~2GPa) on the seed by forming a core/shell structure in the early stage of the reaction.